Investigation on light effect on spatial illusion resulting from forced perspective

Abstract

Linear perspective is a drawing system that can transform geometry from conceptual form to perceptual, and thus it is an essential tool for designers to predict the spatial perception of proposed construction designs. Linear perspective is also identified as an effective pictorial depth cue that can provide the visual information necessary to retrieve the three-dimensional sense of depth from both the two-dimensional retinal images and drawn pictures. As a result, linear perspective has been used as an effective design strategy to create forced perspectives that can exaggerate the depth perception of architectural scenes. Light has also been observed to influence the perceptual judgment of depth in an architectural scene. Luminance contrast has been proven through perceptual studies conducted using the perceptually realistic computer-generated environment to be an effective depth cue that can create illusory depth effects. In this study, the interrelationship of the size and tone-related depth cues of forced perspective and luminance contrast, respectively, are investigated in a three-dimensional setting. The Colonnade Spada architectural space was designed based on forced perspective to create illusory depth. The original design has a series of skylights that no longer exist. For this study, the Colonnade Spada (with and without skylights) was simulated in a digital environment. Psychophysical experiments were conducted to investigate whether the luminance contrast introduced by the skylights would affect the illusory depth effect created by the distorted structural configuration caused by forced perspective.

GRAPHICAL ABSTRACT

Keywords:

• Forced perspective
• light
• depth perception
• spatial illusion

Acknowledgements

The author would like to express his gratitude to the Ministry of Science and Technology, Taiwan, for the financial support they provided through grant NO: MOST 103-2221-E-027-055-. The author would also like to thank the people who participated in the experiments.